Basically ive had a Creative X-fi Xtreme audio card for about a month, its been working every single day since then, but today when i switched on my pc and tried to play music in media player i got a error message saying something like "you dont have any sound device conneted or it is not functioning" or words to that effect, so i took the side of the case off and pulled the card out gave it abit of a blow and put it back in firmly but still no joy, so i then plugged the card into a different pci slot and its now working? does that mean the other pci slot has broken or something? or maybe a hair or dust has got in there somewhere? i cant think of anything else, the main thing is my card isnt broken and its working right now, but id still like to know whats going on, any ideas?

Sometimes its not the PCI slot. Just as an experiment (if u want to), try unplugging the sound card, starting your computer. then, after its COMPLETLY finished, shut it down and put the card back in the sus PCI slot.
I had this problem, and my card (network card tho) wasn't working because my computer randomly decided to ignore it. i was running windows....what cn i say?

yeah i think its probably just windows not detecting the sound card, i mean my motherboard is only like 2- maybe 3 years old max, and the pci slots havent had much use either.

I would do what you said but the pc is tucked away under my desk and its a big case so i cant be bothered dragging it back out agian! lol anyway so yeah you dont think its anything to do with my pci slot/hardware, you just think its windows being an arse!?